Exactly what I thought when I was staring at the answers, frustrated that I had to take a wild stab in the dark before being able to post... Unfortunately I wasn't successful in my attempt to outthink the author.

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Christopher Stobbs (8/24/2009)I agree with the last two posts. I got it wrong cause I can't mind read.

I can think of many examples where the cast is not implicit...

Well, I disagree with those two posts and with you. Is the conversion from tinyint to int implicit, explicit, or forbidden? It's implicit. But as far as I can see you are telling me that because it is perfectly valid to write declare @integer int declare @octet tinyint select @octet = 0 select @integer = cast (@octet as int)the conversion from tinyint to int is explicit. Well, I think that's a very strange point of view.

The descriptions in BOL seem to me quite clear. In fact there's even a nice matrix showing which conversions are implicit, which explicit, and which forbidden. It's been there since SQL 2000. It's still there in SQL 2008 R2. [url=http://msdn.microsoft.com/en-us/library/ms187928%28SQL.105%29.aspx][/url]

Incidentally I recently created a view around OPENQUERY() - data coming from a linked server. Which may have been not the best way to do what I was doing. But anyway, I thought it could be useful to name and CAST to type the columns of the OPENQUERY results - that is, to express explicitly outside the OPENQUERY term the expected columns. But is that worthwhile, or does it perhaps even create a problem?

I haven't been doing the problems lately because I realised if I pass on one that's too hard it doesn't count in the game, and my score looks better than it is. Like Who Wants to Be a Millionaire, I can look at the question and decide to ignore it and keep what I've got. Maybe the score system should keep count of that. I mean, I also don't want to guess, particularly on a point I don't currently understand but may need to at a later date.